1. Field of the Invention
The present invention relates generally to a device for detection conditions of outdoor exercises, and in particular to a device for detecting exercise conditions of bicycle riding by employing both satellite positioning signals received from satellites of a Global Positioning System (GPS) and exercise signals provided by sensors mounted on the bicycle/rider.
2. The Related Art
Exercises have been an important daily activity for modern urbanites. Exercise devices for both indoor and outdoor exercises are commonly available in the market. To ensure the result of exercise, some exercise devices are equipped with an exercise detection device that detects the exercise conditions and shows the detection result to the users. For example, a senor can be mounted on the pedal crank of a bicycle to detect and record the revolution and rotation speed of bicycle wheels. Independent detection devices are also available for detection of exercise conditions, such as a step counter that is attached to the body of a user to count the number of steps/strides that the user takes.
Most of the exercise detection devices are of single function designs. In other words, they detect only one particular kind of signal, such as signal of physical condition of a user or signal of motion of an exercising device, for example speed of a moving bicycle. Devices that receive two kinds of signal for detection of exercise conditions, to the best the inventor knows, are not available in the market.
Global positioning system (GPS) is well known for detecting the position of an object with the aids of radio frequency transmission from satellites. Satellite positioning signals obtained from GPS allows a user to know the position of an object at any particular time points and, based on the data of positions, the speed and moving distance can also be obtained. The GPS also provides data of altitude of the object in a global sense. Due to the fact that transmission of GPS signals between the satellite and a user may be interfered with by large objects that shield between the satellite and the user, GPS signals cannot actually reflect the exercise condition timely. In addition, taking bicycle riding as an example, the GPS provides only the information of displacement, speed and altitude of the bicycle and the rider. However, there is no way that a user of the GPS system can know information regarding pedaling of the rider, such as the pedaling speed (the rotational speed of the crank).
Thus, the present invention is aimed to provide an exercise detection device that employs signals from different sources for providing more precise condition of exercise to a user.